1. Field of the Invention
The present general inventive concept relates to a stereo sound reproducing system, and more particularly, to a method and apparatus to generate a spatial stereo sound by processing a 2-channel stereo sound signal reproduced through a medium, such as a CD and MP3 into the spatial stereo sound.
2. Description of the Related Art
Recently, technologies enabling a 3-dimensional stereo sound through a 2-channel headphone, earphone, or speaker system have been implemented.
Also, in order to implement this stereo sound through the 2-channel earphone, headphone, or speaker system, stereo enhancement systems based on process coding audio information have been being developed.
A conventional stereo enhancement system is disclosed in U.S. Pat. No. 6,597,791.
Referring to FIG. 1, a conventional stereo enhancement system 10 receives left channel (L) and right channel (R) signals 12 and 14 and generates a stereo sound effect of two channels 60 and 62 by using a difference signal 34 and a sum signal 22 of left and right channels 18(24) and 20(26) using an adder 16 and a subtractor 32. That is, the stereo enhancement system 10 combines the left and right channel signals 18(24) and 20(26), the difference signal 34 and the sum signal 22 of the two channels to emphasize the stereo sound effect. At this time, the difference signal 34 is generated as a modified difference signal through a plurality of filters 44 and 48 and an attenuator 46 of an equalizer 40. The two channels 60 and 62 are generated using adders 58 and 56. The equalizer 40 receives an input through a terminal 42 and generates three signals 50, 52 and 54 to be transmitted to the adders 58 and 56.
However, since the conventional stereo enhancement system 10, as shown in FIG. 1, does not consider a head of a listener as an important role in recognizing a direction of a sound source, the positioning of a virtual sound source is not performed. Also, since reflected sounds are not generated, the conventional stereo enhancement system cannot provide a spatial feeling.